Bryant communicating thermostat shows code 55; indicates discharge line temperature sensor fault. System may shut down on protection.

Safety first: Turn off power to the outdoor unit and allow time for the compressor and lines to cool.

Steps:

• 1. Locate sensor: Find the discharge line temperature sensor clipped or strapped to the small copper line leaving the compressor.
• 2. Check attachment: Ensure the sensor is tightly clamped to the line with proper insulation over it. Re-secure if loose and re-wrap with insulation tape.
• 3. Inspect wiring: Look for nicks, cuts, or pulled wires between the sensor and the control board. Repair or replace damaged wiring.
• 4. Reseat connector: With power off, unplug and replug the sensor connector at the board to clean contacts.
• 5. Test operation: Restore power and run the system. If code 55 returns, the sensor or board is likely defective and should be tested/replaced by a technician.

Warning: Do not operate the unit with the sensor bypassed; it protects the compressor from overheating.